JANUARY 9, 1936. FLIGHT. 33
The Martin B - 10
bomber has met with
extraordinary suc
cess. With two
Wright Cyclone en
gines of over 700 h.p.
a speed of 215 m.p.h.
is attained. An
improved type is at
present the subject
of Air Corps experi
ments.
-he Boeing bomber, built five or six years ago. With two
Pratt and Whitney Hornets, of a type now obsolescent,
this machine was capable of over 180 m.p.h., and could
earn' a bomb load of 2,400 lb. Its two Hornets were
mounted forward of the leading edge of its cantilever wing,
its undercarriage was retractable (but bombs were carried
externally), and its fuselage was characterised by almost
constant depth from nose to tail. This type was never put
into quantity production.
Probably the most successful bomber so far produced in
America is the Martin, the B-10 version of which is, per
haps, the best known. A description of this type was given
in Flight of September 19 last year. In everyday use with
the U.S. Army Air Corps, a number of Martins are put
ting up some brilliant performances, and not long ago a
group of them distinguished itself by making a fast survey
trip into Alaska. Without doubt the Martin has a higher
performance than any machine of its type in service with
any air force.
A Neu> Martin
The past few months have seen the appearance and
initial tests of a new and much-improved Martin bomber
—a development of the B-10—which is entered in the
present U.S. bomber competition alongside a new Douglas.
The Boeing entry, the four-engined 299, was destroyed in
an accident. Like its forerunner, the Martin is a mid-
wing a-11-metal monoplane carrying a normal crew of four
or five. Three Browning guns are provided, and the bomb
load is stowed internally, being released through trap
doors in the "belly." The engines are of an improved
Wright Cyclone type, giving over 800 h.p. each, and driving
Hamilton constant-speed aircrews. The span is 76ft., the
all-up weight about ten tons, and included in the equip
ment are a radio compass, automatic pilot and two-way
radio. Having regard to the cleaning-up (the three cock
pit installations merge into the lines of the fuselage more
efficiently than on the B-10) and the extra power, the
maximum speed should be at least 235 m.p.h., for the B-10
does 215 m.p.h. at 6,500 feet.
Some time ago, it is reported, the French Governmeut
was considering ordering a number of Martins, but no
contract was ever placed. One French manufacturer, who
has lately produced a somewhat startling multiplace do
combat monoplane comparable with the Martin, has taken
the somewhat unethical course of publishing, in his house
journal, a tabulated comparison between his product and
the Martin B-10. He proceeds to show that the French
machine stands head and shoulders above the American
on almost every score. Certain discrepancies appear to
have crept in, however, and as a document of extreme
technical importance the table has not been received with
acclamation.
One of the greatest blows struck at American military
aviation during recent years was the recent disaster to the
Boeing 299 bomber. The story goes that the pilot took
off for a test flight with locked controls, and that the
machine crashed from 200 feet. Measuring about 100 feet
in span (roughly equal to the Fairey Hendon, which is less
than half as powerful) the 299 was fitted with four Pratt
and Whitney Hornets mounted in line abreast along the
leading edge of the cantilever wing. The undercarriage
retracted into the nacelles of the inboard power units.
Armament installations of a secret nature featured in the
design, and an automatic pilot, two-way wireless and a
radio compass were specified. Before it was destroyed
the 299 distinguished itself by flying for 2,300 miles at
an average speed of 232 m.p.h.
There are indications that the four-engined bomber will
soon assume a prominent place in the equipment of the
major air services. The Boeing company is said to have
up its sleeve another machine of this type, to be fitted,
according to one report, with prestone-cooled Allison " X "
engines of about 1,000 h.p. each, and in Europe the Farman
pioneer type in the development of the modern long-range high-speed bombing monoplane, this Boeing, built five or six
years ago, was capable of 180 m.p.h.